1. Field of the Invention
The present invention relates to an immersion system, an exposure apparatus, an exposing method, and a device fabricating method.
2. Description of Related Art
As disclosed in U.S. Patent Application Publication No. 2006/0250593 and U.S. Patent Application Publication No. 2007/0296939, among exposure apparatuses used in photolithography, an immersion exposure apparatus is known that exposes a substrate with exposure light through a liquid.
In an immersion exposure apparatus, it is critical to satisfactorily fill the optical path of the exposure light between the substrate and an optical member, such as a projection optical system, with the liquid. If the optical path cannot be satisfactorily filled with the liquid, for example, if a gas portion, such as a bubble, occurs in the liquid, then exposure failures may occur; for example, defects may occur in the pattern formed in the substrate. In addition, if the substrate is moved at high speed in the state wherein the optical path between the substrate and, for example, the optical member is filled with the liquid, then it becomes difficult to satisfactorily and continuously fill the optical path with the liquid, and the liquid may leak out from a prescribed space, remain on the substrate, or the like. Furthermore, the heat of vaporization of the leaked or residual liquid may induce changes in the temperature of the optical path, thermal deformation in the various members, such as the substrate, or the like. In this case, too, exposure failures may occur. As a result, defective devices could be produced.
A purpose of some aspects of the present invention is to provide a liquid immersion system that can satisfactorily fill an optical path of exposure light with a liquid. Another purpose of the aspects of the present invention is to provide both an exposure apparatus that can prevent exposure failures and an exposing method. Yet another purpose of the aspects of the present invention is to provide a device fabricating method that can prevent the production of defective devices.